Some paths on the adventures are blocked with iron crates. There will be a mutant [randomly] you will have to defeat the creatures like you normally do. If you keep attacking the creature while it needs to be jack, it will turn to mojo and another creature will appear. When it needs to be jacked, jake it and then you can destroy those darn iron crates with your control of the creature.
Finding Tiki Masks
Finding Tiki Masks are easy! You can find them in higher places are secret areas. Earn the move {Double Jump} by collecting mojo and you could jump higher to get to a Tiki Mask. In secret areas, all the way at the bottom of most of the levels, jack a creature to destroy things that block you. I bet you will find Tiki Masks! Now!